Switchblade-newbee

J

jimthebarron

New Member
Hi

Jim from the U.K. here, I saw the motorised Ratfink a few weeks ago and just had to build something similar!

So I bought a second hand Swithblade from ebay along with a gru-bee 80cc engine kit.

I know I have to fabricate front and rear mounting brackets for the engine to off set it which shouldn't be a problem, but I am not sure about the rear wheel and coaster brake.

I can see from other peoples builds the height and angle of the engine location, but before I spent ages with the back wheel I wondered if I could run the coaster brake with this engine kit?

Any help would be great
 
Yes, use a coaster brake. That's the easiest way to go!
You'll also have to mount the new sprocket far enough out for the chain to clear the 3" tire.
 
Last edited:
Hi
Thanks for the info.

But if I mount the chain wheel like this (pic) the chain wont clear the tyre and the bolt heads would catch the coaster arm. Also the chain wheel doesn't seat very well over the bearing dust cover, if I take the dust cover off it seats very well but obviously the chain would realy eat into the tyre.

chain.jpg
 
You must keep the dust cover on & drill the center hole in the sprocket as large as possible & bend the brake arm into a 'Z' shape; & then add another rag joint to get the sprocket out far enough.

Or you can simply purchase a 'Sportsman' hub adapter & sprocket. The sportsman hub adapters are taller that the other brands to allow the use of large 3" tires. You will still have to keep the dust cover on & bend the brake arm though. ;)
 
Hi
I see what you mean about the brake arm, but what is a rag joint and if I make the hole in the chain ring bigger it will sit over the dust cover and closer to the spokes.

Cheers for your help
Jim
 
jimthebarron said:
Hi
I see what you mean about the brake arm, but what is a rag joint and if I make the hole in the chain ring bigger it will sit over the dust cover and closer to the spokes.

Cheers for your help
Jim
Click to expand...

The rag joints are those two big black rubber donuts that go between the sprocket & the spokes... & you make the center hole big enough to almost touch the 9 smaller holes.
 
Your company makes some good looking stuff , any chance of makeing some bike parts for general sale? I only have a few thousand ideas....
Nice work on mount ,can't wait to see what finished product looks like.
 
Always looking for parts to make especially when it is something I am realy interested in, what sort of thing are you thinking of - possibly something a lot of owners would like.

Cheers
Jim
 
Depends jim ,how much do you pay consultants ?:) Truth be told I think we have all thought the same things, tool boxs , batt boxs , head-n- tail lamp, farrings, saddlebags, rack tanks, etc. Deff be cool to make an instrument housing for handlebars ?
Idea's I got in spades ,furnace and foundry ,not so much!
Back when they used to teach shop skill's in highschool , we cast all kinds of crap, but the goal was to move into rapid prototyping quickly . I moved on to cad/cam and haven't touched green sand since.
Would love to make / have this kind of gear ,so there is a small market . Prob need to take a bike like the cranbrook and make stuff for that frame or stick to clamp on's?
Looking forward to hearing your take on this , as it's your industry, perhaps in a new thread or by pm your choice.
 
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